Oscillatory circuit



Nov 29, 1938. c. w. HANSELL 2,138,161

OSCILLATORY CIRCUIT Original Filed May l, 1951 42 LENGTH OF CONNECTION ADJIJSTABLE INVENTOR. CLARENCE W. HANSELL ATTORNEY.

Patented Nov. 29, 1938 Clarence W. Hansell, Port fJefiers on, 'N.'Y., as-

signor to Radio Corporation of America, a corporation of Delaware Original application May 1, 1931, Serial No.

534,255,.now Patent No. 2,017,093, dated October 15, 1935. Divided and this application March 19, 1935, Serial No. 11,896. Renewed 0ct0ber5, 1937., In Australia April 18, 1932 24 Claims. (01. 25036) This invention is a division of my copending application Serial No. 534,255, filed May 1, 1931, which has issued as United States Patent No. 2,017,093, dated October 15, 1935, and relates to high frequency circuits, particularly to oscillatory circuits and concentric frequency control transmission lines'therefor.

In my United States Patent No. 1,945,546, granted February 6, 1934, I have described a system employing a resonant transmission line for frequency control whereby the frequency of oscillations generated by the generator is maintained constant. The frequency controlling action of the line may be attributed to the fact that the line forms the equivalent of a sharply tuned resonant circuit whose reactance changes rapidly with change of frequency and which change or reactance may be utilized to keep the frequency of an oscillator relatively constant.

One of the objects of the present inventionis to provide an improved frequency control transmission line and/or circuit. 7

A further object of my present invention is to provide an improved form of resonant line associated with an electrondischarge device oscillator which line shall be radiationless and free from pick-up of extraneous alternating current energies which might affect the operation of the oscillator.

According to the present invention, the resonant line is a low loss, radiationless affair, made of an inner conductor and, preferably, a concentric hollow outer conductor whereby standing waves on the conductors (out of phase) neutralize each other, thereby preventing radiation; The line is a low loss affair and has uniformly distributed inductance and capacity and consequently may be employed for maintaining to a high degree of constancy'the frequency of oscillations generated by an electron discharge device system. The line has the effect of a sharply tuned resonant circuit and therefore its reactance changes rapidly with change in frequency, and it is this characteristic which is utilized to keep the frequency of the oscillator constant. The resonant frequency of theline is determined chiefly by the length of the line, and forthis reason it is important that the length be kept constant in order to maintain a high degree of frequency stability.

Other objects, as well as features and advantages, will appear in the subsequent detailed description which is accompanied by a single drawing showing an oscillation generator circuit equipped with the improved concentric frequency controltransmission line in accordance with the principles underlying the invention.

The single figure of the'drawing illustrates a Y whereby it exerts a controlling effect upon the frequency of'oscillations generated. It should be understood that resistor '44 may have a choke coil in series and a condenser in parallel with it for biasing purposes, Also, the condenser 42, or

the length of connections to it may be made variable for obtaining exact adjustment of frequency, or, if desired, the line may have a slidably adjustable section, like a trombone to serve the same purpose. By virtue of the concentric arrangement of the resonant line, radiation or pick-up from other sources is prevented. The inherent capacity'of electron discharge device 2 is'indicated by the dotted lines, and, if this is insufficient to start oscillations, it may be supplemented by a capacity 5 connected in parallel to'the anode and grid of tube 2. Asindicated, output energy may be taken from a circuit 46 inductively coupled to the tuned output circuit 4 of electron discharge device oscillator 2. Obviously, any of the other well known methods of coupling may also be used.

Line 6 is preferably made at least a plurality ofhalf wave lengths long at the operating frequency.

What is claimed is:

i 1. An oscillation generator comprising an electrondischarge device having a cathode and a pair of cold electrodes, said cold electrodes being regenerativel'y coupled together, an output circuit having inductance and capacitance connected between one of said cold electrodes and said cathode, and a frequency stabilizing circuit connected between said other cold electrode and said cathode, said frequency stabilizing circuit comprising a linear tube, and a linear conductor within said tube, and adjustable means coupling said tube and conductor together at points removed from the points of connection of said stabilizing circuit to said cathode and last cold electrode for adjusting the frequency of said generator. g

2. An oscillation generator comprising a multielectrode device having an anode, a cathode and a control grid, a resistance connected between said control grid and cathode, a circuit having inductance and capacitance connected between said anode and cathode, and a frequency stabilizing circuit connected to said cathode and control grid, said frequency stabilizing circuit comprising a straight metallic tube, and a coaxial conductor within said metallic tube, said tube and conductor being at least a plurality of half wave lengths long at the frequency of the generator.

3. An oscillation generator comprisinga multielectrode device having anode, cathode and grid,

electrodes, a circuit having'inductance and capacitance connected between said anode and cathode electrodes, a straight, metallic tube connected to said cathode electrode, and a substantially straight conductor lying within said tube connected to said grid electrode, said tube and conductor being at least a plurality of half wave lengths long at the frequency of the generator.

4. An oscillation generator comprising an electron discharge' device having an anode, a cathode and a grid, a'circuit having inductance and capacitance connected between the anode and cathode, a resistance connected between the grid and cathode, a straight metallic tube connected tor to said grid, said tube and conductor being at to said cathode and to ground, and a substantially straight conductor lying within said tube connected to said grid, said tube and conductor being at least a plurality of half wave lengths long at the frequency of the generator.

5. An oscillation generator comprising an electron discharge device having an anode, a cathode and a grid, a circuit having inductance and capacitance connected between said anode and cathode, a resistance connected between said grid and cathode, said cathode being grounded, a straight metallic tube, means grounding said tube, a substantially straight conductor lying within said tube, and means for connecting said conducleast a plurality of half wave lengths long at the frequency of the generator.

6. An'oscillation generator comprising an electron discharge device having an anode, a cathode i and a grid, a tuned circuit comprising an inductance shuntedby a condenser connected between said anode and cathode, a resistance connected between said grid and cathode, a frequency sta-' bilizing means comprising a straight cylindrical metallic tube connected to said cathode, a straight conductor lying within said tube connected to said grid, and a condenser connecting the end of said conductor removed from said grid to said cylindrical metallic tube.

'7. An oscillation generator comprising a multielectrode device having anode, cathode and grid electrodes, a tuned output circuit having inductance and capacity connected between said anode and cathode electrodes, a hollow metallic tube connected to said cathode electrode, a substantially straight conductor lying within and spaced from said tube connected to said grid electrode, a' reactance connecting the end of said conductor removed from said grid to said tube, and a feed back capacity coupled between said anode and ance shunted by a condenser connected between metallic tube connected to said cathode, a straight I said anode and cathode, a resistance connected between said grid and cathode, a frequency stabilizing means comprising a straight cylindrical quency of said oscillation generator.

10. An oscillation generator comprising an electron discharge device having an anode, cathode and grid, a tuned output circuit coupled to said anode, and a frequency stabilizing circuit coupled to said grid and cathode, said stabilizing circuit comprising a pair of long, coaxial, concentric conductors of unvariable length at least a plurality of half wave lengths long at the operating frequency.

11. An oscillation generator comprising an electron discharge device having a cathode and a grid, a frequency stabilizing circuit comprising a pair of coaxial concentric conductors at least a plurality of half wave lengths long atthe frequency of the generator, connections from said grid and cathode to points on said conductors substantially near one of their adjacent ends, and variable means for coupling said conductors together at points substantially near their other adjacent ends for adjusting the frequency of the oscillation generator.

12. An oscillation generator comprising a multi-electrode device having anode, cathode and grid electrodes, a tuned circuit having inductance and capacitance connected between said anode and cathode electrodes, a metallic tube connect,- ed to said cathode electrode, and a straight conductor lying within said tube and connected to said grid electrode, said tube and conductorbeing at least a plurality of half wave lengths long at the frequency of the generator, and adjustable means coupling said tube and conductor together at points removed from the points of connection thereof to said cathode and grid electrode for adjusting the frequency of said generator.

13. An oscillation generator comprising anelectron discharge device having anode, cathode, and grid electrodes, a tuned output circuit coupled between said anode and cathode, and a frequency controlling circuit in the form of concentric in ner and outer straight conductors having a length such that said conductors control the frequency of said oscillation generator, one of said conductors being coupled to said cathode and the other to said grid. 7

14. An oscillation generator comprising an electron discharge device having anode, cathode and grid electrodes, a tuned output circuit coupled to said anode and cathode, and a frequency controlling element in the form of a pair of .coaxially arranged parallel straight conductors, each at least a plurality of half wave lengths long at a desired operating frequency, said conductors being coupled to said grid and cathode.

15. An oscillation generator comprising an elecconductor lying within said tube connected to said grid, and a condenser connecting the end of said conductor removed from said grid to said cylindrical metallic tube.

An sc l n. nerato prisin and grid electrodes, a tuned output circuit coupled between said anode and cathode, and a frequency controlling circuit in the form of a pair of coaxially-arranged, parallel, straight conductors, one of said conductors being coupled to said cathode and the other to said grid, and means for adjustably coupling said conductors together.

18. An oscillation generator comprising an electron discharge device having an anode, a cathode and a grid, a circuit having inductance and capacity connected between said anode and cathode, a frequency stabilizing means comprising a straight cylindrical metallic tube connected to said cathode, a straight conductor lying within.

said tube, a connection near the cathode connection to said tube from said inner conductor to said grid, and means capacitively coupling the ends of said conductor and tube removed from said grid and said cathode connections.

19. An oscillation generator comprising an electron discharge device having anode, cathode, and grid electrodes, a high frequency output circuit connected to said anode and cathode, a frequency controlling circuit in the form of a pair of coaxially arranged inner and outer. straight conductors, said inner and outer conductors being coupled at adjacent ends to said grid and cathode, and means capacitively coupling said conductors together substantially at the other adjacent ends.

20. An oscillation generator comprising a multi-electrode device having anode, cathode and grid electrodes, a tuned output circuit having inductance and capacity connected between said anode and cathode electrodes, a hollow metallic tube connected to said cathode electrode, a substantially straight conductor lying within and spaced from said tube connected to said grid electrade, a reactance connecting the end of said conductorremoved from said grid to said tube, and a. capacity between said anode and grid for establishing feed-back.

21. An oscillation generator comprising an electron discharge device having an anode, a cathode and a grid, a circuithaving inductance and capacity connected between said anode and cathode, a resistance connected between-said grid and cathode, a frequency stabilizing means comprising a straight cylindrical metallic tube connected to said cathode, a straight conductor lying within said tube connected to said grid, and a condenser connecting the end of said conductor removed from said grid to said cylindrical metal- 'lic tube.

22. An oscillation generator. comprising an electron discharge device having a cathode and a grid, a frequency stabilizing circuit comprising a pair of inner and outer coaxial conductors, connections from said grid and cathode to points onsaid conductors substantially near one of their adjacent ends, and variable means for coupling said conductors together at points substantially near their other adjacent ends for adjusting the frequency of the oscillation generator.

23. An oscillation I generator comprising an electron discharge device having an anode, a cathode'and a grid, a tuned circuit connected between said anode and cathode, a frequency stabilizing means comprising a straight cylindrical metallic tube connected to said cathode, a straight conductor lying within said tube connected to said grid, and a condenser connecting the end of said conductor removed from said grid to said cylindrical metallic tube.

24. An oscillation generator comprising an electron discharge device having'anode, cathode, and grid electrodes, a tuned output circuit coupled between said anode and cathode, and a frequency controlling circuit in the form of a pair of coaxially arranged inner and outer straight conductors, said inner conductor being coupled to said grid and said outer conductor coupled to said cathode, and means for adjustably coupling said conductors together.

CLARENCE W. HANSELL. 

